1. Field of the Invention
The present invention relates to a method for producing an ink-jet head for discharging an ink onto a recording medium. The present invention also relates to the ink-jet head.
2. Description of the Related Art
Japanese Patent Application Laid-open No. 11-334087 (FIG. 1) describes a method for producing an ink-jet head including a vibration plate and a piezoelectric film formed on the vibration plate wherein the vibration plate is continuously formed on a substrate arranged with a plurality of pressure chambers to have such a size that all of the pressure chambers are covered with the vibration plate, the vibration plate and the piezoelectric film being composed of metal materials having coefficients of thermal expansion similar to one another. According to this method, when the piezoelectric film is formed on the vibration plate, a stack or laminate, which is composed of the vibration plate and the piezoelectric film, is suppressed from causing any warpage which would be otherwise caused by the difference between the coefficients of thermal expansion of the vibration plate and the piezoelectric film.
However, in the case of the method for producing the ink-jet head described in Japanese Patent Application Laid-open No. 11-334087, any mutual diffusion occurs between the materials for constructing the vibration plate and the piezoelectric film, and the crystal growth of the piezoelectric film is inhibited during the calcination of the piezoelectric film, when the piezoelectric film is thermally formed or calcinated on the vibration plate. As a result, the performance of the piezoelectric film is deteriorated.